1. Technical Field
Various implementations relate to a nonvolatile memory device, and more particularly, to a variable resistance memory device and a method of manufacturing the same.
2. Related Art
In recent years, with demands on semiconductor devices with high performance and low power, next generation semiconductor memory devices with non-volatility and no refresh have been researched. As one of the next-generation semiconductor memory devices, variable resistance memory devices have been suggested. Such and there are phase-change random access memory devices (PCRAMs), resistive RAMs (ReRAMs), magnetic RAMs (MRAMs), spin-transfer torque magnetoresistive RAMs (STTMRAMs), and polymer RAMs (PoRAMs) as the variable resistance memory devices.
The variable resistance memory devices perform a memory operation to have a set state or a reset state by controlling a phase-change material, which constitutes a data storage unit, to a crystalline state or an amorphous state.
Here, since more current is required in switching to the reset state of the variable resistance memory device than in switching to the set state, the current for switching to the reset state, that is, a reset current has to be lowered to obtain a high degree of integration.
In recent years, variable resistance memory devices having a confined structure are suggested to obtain a high degree of integration. There is a need for improving reliability of the variable resistance memory devices by improving stability of a process in a method of fabricating the variable resistance memory devices having the confined structure.